VINEA: An Architecture for Virtual Network Embedding Policy Programmability

Network virtualization has enabled new business models by allowing infrastructure providers to lease or share their physical network. A fundamental management problem that cloud providers face to support customized virtual network (VN) services is the virtual network embedding. This requires solving the (NP-hard) problem of matching constrained virtual networks onto the physical network. In this paper we present VINEA, a policy-based virtual network embedding architecture, and its system implementation. VINEA leverages our previous results on VN embedding optimality and convergence guarantees, and it is based on a network utility maximization approach that separates policies (i.e., high-level goals) from underlying embedding mechanisms: resource discovery, virtual network mapping, and allocation on the physical infrastructure. We show how VINEA can subsume existing embedding approaches, and how it can be used to design novel solutions that adapt to different scenarios, by merely instantiating different policies. We describe the VINEA architecture, as well as our object model: our VINO protocol and the API to program the embedding policies; we then analyze key representative tradeoffs among novel and existing VN embedding policy configurations, via event-driven simulations, and with our prototype implementation. Among our findings, our evaluation shows how, in contrast to existing solutions, simultaneously embedding nodes and links may lead to lower providers' revenue. We release our implementation on a testbed that uses a Linux system architecture to reserve virtual node and link capacities. Our prototype can be also used to augment existing open-source “Networking as a Service” architectures such as OpenStack Neutron, that currently lacks a VN embedding protocol, and as a policy-programmable solution to the “slice stitching” problem within wide-area virtual network testbeds.